.- help for ^gpfobl^ by Herve M. CACI, March 2003 .- Rotation after Exploratory factor analysis / Principal components analysis -------------------------------------------------------------------------- ^gpfobl^ [, Factors(#)] Description ----------- This is the translation into Stata programming language of the programs that appear in the paper: Gradient Projection Algorithms for Arbitrary Rotation Criteria in Factor Analysis by Coen A. Bernaards & Robert I. Jennrich (http://www.stat.ucla.edu/research) If this command is used after ^factor^, you have to get the matrix of unrotated loadings. That is, .matrix A=get(Ld) .gpfobl A, oblimin(.50) By default the number of factors is the number of columns of the inputted matrix. However, the user can choose to rotate a lower number of factors. .matrix A=get(Ld) .oblimin A,f(3) Available oblique rotation criteria are: 1. OBLIMIN(gamma): by default, gamma==0.50. If the user specifies gamma==0 then the rotation is QUARTIMIN, and if the user specifies gamma==1 then the rotation is COVARIMIN. 2. OBLIMAX: no parameter needed. 3. IPS: Bentler's Invariant Pattern Simplicity (no parameter needed). 4. CFerguson(kappa): this is in fact a family of rotations. - QUARTIMAX if kappa==0 - VARIMAX if kappa==1/p - EQUAMAX if kappa==k/(2*p) - PARSIMAX if kappa==(k-1)/(p+k-2) - Factor parsimony if kappa==1 where k is the number of the number of factors and p is the number of variables 5. GEOMIN(epsilon): by default epsilon==0.01.